Paediatric Radial Neck Fracture
Radial neck fractures are uncommon and account for 8% of all elbow fractures in children.
Associated elbow injuries occur in 50% of radial neck fractures. These include avulsion of the medial epicondyle, fracture of the olecranon, or proximal ulna.
Radial neck fractures can be classified according to:
Anatomical location: metaphyseal, physeal (most common Salter-Harris type II)
Degree of displacement
The most common mechanism is a fall onto the outstretched arm with valgus stress at the elbow. They can also occur as a result of a posterior dislocation or reduction of the elbow joint.
There is usually pain, tenderness, and swelling over the lateral aspect of the elbow and decreased forearm rotation (pronation/supination).
The deformity is not typically a feature unless there are associated injuries (elbow joint dislocation, ulna shaft fracture)
All fractures should be assessed using the Advanced Trauma Life Support (ATLS) principles to ensure associated and potentially significant injuries are identified.
Anteroposterior (AP) and lateral view of the elbow should be ordered. The degree of forearm rotation should be the same in each view (e.g. mid-position). This is to ensure that the views obtained from the proximal radius are orthogonal.
If the patient is unable to fully extend the elbow, the AP view of the elbow may not be a true AP view of the radius. In this situation, a separate AP view of the proximal radius may be needed to better assess the displacement.
The radial head should point to the capitellum in all views.
Management is based on the amount of angulation between the radial head and shaft. Fractures that are angulated ≤30 degrees, <10% translation, and <10 years of age do not require reduction.
Fractures with angular deformity greater than 30 degrees usually require reduction.
Any fracture reductions should be performed under x-ray image intensification under general anesthesia. However, there are several here:
The closer the child is to skeletal maturity, the less time there is for remodelling (in this situation, angular deformity >15 degrees may not be acceptable)
The true degree of angulation may be more than is shown on any one standard x-ray view
The translation may compound the effects of angulation
Associated injuries mean the degree of angulation may increase
Intra-articular physeal fractures (Salter-Harris type III and IV) have their criteria for the reduction.
Emphasis should be placed on the elevation of the limb (elbow above the heart) for the first 48 hours and active finger mobilization.
Back slab and sling should be worn under clothing and not through the sleeve.
Most do well but some become stiff (loss of forearm rotation) even with optimal treatment. A good outcome is expected for minimally angulated isolated fractures.
As with other injuries around the elbow, especially when they occur in combination, there is the potential for a poor outcome. Close follow-up (including serial x-rays) is important. Whilst good management decreases this likelihood it does not remove it.
Children generally recover their elbow range of motion well and do not require physiotherapy.
Failure to appreciate/manage associated injuries
Malposition leading to dysfunction of the radiocapitellar joint and/or proximal radioulnar joint
Development of radioulnar synostosis, whilst not common, is a significant complication
AVN collapse of the radial head (predominantly in cases that required open reduction)